This invention concerns a device to distribute air for glass-fronted cabinets and display counters as set forth in the main claim.
The invention is applied in the field of production of glass-fronted cabinets, display counters or other similar modules used to conserve, display and sell foodstuffs which have to be kept in appropriate climatic conditions of cold or heat.
In the following description we shall describe the example of refrigerated containers, but the invention can be extended to whatever type of glass-fronted cabinet or counter to conserve, display and sell products which have to be kept at a set temperature.
The glass-fronted cabinets or counters are characterised in that they define an at least partly closed volume, climatically conditioned, wherein the products on display are arranged on one or several levels, or are in any case stacked one on top of the other, and wherein the containing volume is delimited at the front part by at least a transparent front-piece which allows customers a complete view of the products.
The state of the art includes refrigerated or heated glass-fronted cabinets and counters for display, wherein food products are conserved and displayed for customers interested in buying them.
The glass-fronted cabinets or counters are usually defined by a thermally conditioned compartment, for example refrigerated, wherein the food products to be displayed are arranged on one or more levels, by a technical compartment, usually located below or behind the refrigerated compartment, and by a motor compartment located inside or outside the counter.
The refrigerated compartment is closed at the front by one or more transparent pieces which allow the customers a complete view of the products; at the rear, it is closed by a possible service door, which can be opened and which allows the assistant to access the refrigerated compartment for the usual sales operations.
The technical compartment communicates with the refrigerated compartment, defining together therewith an air-circulation circuit comprising means to deliver cold air and means to recover the air which is then sent to the refrigerator unit arranged inside the technical compartment.
The air-circulation circuit substantially affects the loading zone of the refrigerated compartment, usually limited at the upper part by the service plane located on the side where the sales assistant, or the person in charge of distributing the products, operates.
A problem which businessmen operating in this field particularly complain of is when the products to be displayed and kept under particular conditions of conservation are arranged on several levels inside the refrigerated compartment, for example on shelves one above the other, or simply stacked so as to form a pile to a certain height on the loading surface.
This happens, for example, in counters to display and sell ice cream or frozen foods, pastry or cake products, bottled or canned drinks, or in display cabinets where meat, salami, dairy products or similar products are conserved.
It has been found that the climatic conditions inside the glass-fronted cabinets are extremely variable and that, for this reason, the products in the upper part of the refrigerated volume are not kept at the required conditions of refrigeration.
This obliges the assistants to place, in the upper part, only products which do not need an intense refrigeration.
This situation is aggravated when, in the upper part of the glass-fronted cabinet, there are sources of light which irradiate heat onto the underlying products.
Various solutions have been proposed to overcome this shortcoming, but they have not been satisfactory.
A first solution provides to arrange an evaporator on the ceiling of the refrigerated glass-fronted cabinet.
This solution, however, creates problems with the correct circulation of air, uniformity of temperature, the formation of ice visible in the upper part of the glass-fronted cabinet, and of water dripping onto the products.
Another solution provides to remove the refrigerated air by means of pipes arranged on the lateral uprights of the glass-fronted cabinet, which may even be activated on command, and to send it laterally, by means of appropriately directed outlets, towards the sides of the shelves on which the products to be refrigerated are arranged.
This solution has the main problem that there is a lack of uniformity in the refrigeration between the lateral zones of the shelves, where the refrigeration is very intense, and the central zone of the shelves and in general of the whole central part of the glass-fronted cabinet.
The products positioned at the sides also create a barrier effect on the correct circulation of the refrigerated air. Moreover, if the shelf is curved, the products are only partly affected by the flow of refrigerated air.
Furthermore, this solution creates the problem that the cooling efficiency of the lower part of the glass-fronted cabinet is reduced when the pipes to remove air are activated.
Finally, there is the aesthetically displeasing effect that the pipes are in view, apart from the further technological and operational complexity to ensure a correct functioning.
Obviously, all this equally applies in the case of a compartment which is heated to conserve, display and sell foodstuffs which have to be kept at a certain temperature.
Another solution is proposed in DE-A-37 04 245, which provides a channel on one side of the refrigerated container suitable to convey cold air into the upper part of the refrigerated compartment, and a channel on the opposite side suitable to recover the air and to convey it towards the technical compartment beneath the refrigerated compartment.
This solution does not solve the problems of a uniform refrigeration, especially in the case of containers which are developed particularly lengthwise, creating colder zones on one side and warmer zones on the other side.
Moreover, it does not solve the problem of the barrier effect created by those products which are located higher in the refrigerated compartment, nor the problem of the possible presence of curved shelves.
DE-A-31 37 961 also proposes a solution to convey refrigerated air into the upper part of a refrigerated container which also functions as a food-warmer.
This solution refers to a container of the cupboard type, not to a display container of the type in question; this solution provides that, in cooperation with the rear wall of the cupboard, there is a further wall able to create a channel to convey air towards the upper part of the container.
DE""961 therefore does not propose any solution for the uniform cooling of products facing towards the customer""s side, arranged in the upper part of a refrigerated compartment for a display container with a transparent front-piece.
The present Applicant has devised and embodied this invention to overcome the shortcomings of the state of the art, and to obtain further advantages as will be explained hereafter.
The purpose of the invention is to achieve glass-fronted cabinets and counters to display and sell foodstuffs, refrigerated or heated, which will ensure uniformity of the climatic conditions throughout the volume of the compartment containing the products, without substantially altering the structure and conformation of traditional glass-fronted cabinets and counters.
Another purpose is to obtain this uniformity of temperature by using means which do not create any kind of constraint of an aesthetic type, and guarantee the correct conditions are maintained so that the products inside the containing compartment can be seen.
A further purpose is to obtain desired and uniform refrigeration conditions irrespective of the length of the refrigerated container and irrespective of the quantity and arrangement of the products arranged on the shelf or shelves to be refrigerated.
A further advantage is that it minimises the technological and operational complexity of the refrigeration or heating unit.
According to the invention, the refrigerated glass-fronted cabinet or counter to which the following description refers comprises a substantially conventional structure, consisting of a refrigerated compartment to conserve, display and sell foodstuffs on one or more levels, a technical compartment and possibly an inner motor compartment.
The refrigerated compartment is defined at the front part by a first or outer transparent element, for example a glass pane or a series of panes, arranged on the customer""s side and normally closed in the usual operating conditions of the glass-fronted cabinet, and at the rear by an optional closing element arranged on the assistant""s side and which can be opened to allow access to the foodstuffs contained therein.
According to a variant, at least the rear closing element arranged on the assistant""s side is associated with automatic drive means which cause the glass to open/close according to whether or not the assistant is near the glass.
According to the invention, inside the refrigerated compartment and in co-operation with the first transparent element located on the customer""s side there is at least another transparent conveyor element defining at least a transit and guide channel for the refrigerated air.
The transparent conveyor element is suitable to convey and send the air delivered by the delivery means, arranged in the technical compartment of the glass-fronted cabinet, to the upper part of the refrigerated volume of the said glass-fronted cabinet.
The conveyor element extends substantially along the whole length of the glass-fronted cabinet, so as to ensure the refrigerated air is distributed over the whole front thereof, in a completely uniform manner irrespective of the length of the cabinet and irrespective of the load and the arrangement of the products on the refrigerated shelves.
With this solution, the air collected by the delivery means is conveyed upwards and made to exit in the upper or in any case the intermediate part of the glass-fronted cabinet and then directed downwards, where it is distributed uniformly over the whole volume of the refrigerated compartment.
This solution therefore allows to extend the loading zone of the food products inside the refrigerated compartment, overcoming the limitation of traditional glass-fronted cabinets or counters which restrict the loading zone only to the part below the service plane.
Hence the invention allows to guarantee the required conditions of refrigeration even on products kept at a higher level or on levels higher than the service plane or work plane, for example arranged on shelves above the loading surface.
The air is distributed onto the products frontally, from above and in a uniform manner along the whole cabinet; this ensures refrigeration conditions which are constant for all the products aligned on the display shelves.
Moreover, as it travels upwards, the cold air does not meet any sudden element to deflect it, or any significant variation in the section of flow which might cause both a reduction in its cooling power and also high losses of load.
At the same time, since it is transparent, the conveyor element does not create any impediment to the visibility of the products on display, since it is substantially invisible from outside.
Moreover, this solution does not create any complications from the technological point of view either, since the system to deliver, process and recover the air is in no way influenced or modified by the presence of the conveyor element.
A further advantage of the invention is that it does not create any risk of condensation dripping onto the products, since any possible condensation can be formed only on the side of the conveyor element facing towards the transparent front piece.
Another advantage is that the conveyor element allows easy cleaning and maintenance.
According to a variant, in co-operation with the outlet of the conveyor element there is a deflector element suitable to direct the refrigerated air downwards, in such a way as to guarantee a more uniform distribution over the whole volume of the refrigerated compartment.
According to a further variant, the conveyor element has slits for the passage of air, arranged in co-operation with the loading surface and/or with optional shelves at the various heights of the glass-fronted cabinet.
The slits may or may not cooperate with deflector and guide elements to direct the air more efficiently towards the products to be refrigerated.
According to further variants, the conveyor element can be defined by two or more transparent elements arranged one in front of the other in co-operation with the glass on the customer""s side, to ensure a better heat insulation with respect to the outside environment.
According to another variant, the transparent air-conveyor element can be replaced with an identical element of a different height, so that it is possible to vary the outlet level of the refrigerated air.
According to a further variant, the transparent air-conveyor element can slide upwards so as to define at will the position of the outlet of the refrigerated air on the height of the glass-fronted cabinet.